Crankcase ventilation system



June 15, 1965 J. w. HuMPHREYs CRANKCASE VENTILATION SYSTEM Filed Jan.22, 1964 FIG.I

INVENTOR. Jay/V zd. #0MM/kfw FIG. 4

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United States Patent O 3,189,012 CRANKCASE VENTlLATION SYSTEM John W.Humphreys, Muskegon, Mich., assignor t Johnson Products, Inc., Muskegon,Mich., a corporation of Michigan Filed Jan. 22, 1964, Sor. No. 339,391Claims. (Ci. 123-119) This invention relates to a crankcase ventilationsystem, and more particularly to a unique crankcase air inlet valve incombination with a positive pressure crankcase exhaust control system tothe intake manifold.

This invention relates to my prior invention in Patent No. 3,108,581,assigned to the assignee herein.

My prior invention, disclosed and claimed in the above identied patent,utilizes a sealed crankcase exhausting system to the intake manifold. Aow control valve is in the connecting conduit. lt allows tiow of blow-bygases from the crankcase to the manifold when opened by a controlelement exposed on one side to atmospheric or other standard pressureand on the other side to positive crankcase pressure. Thus, it opens inresponse to the excess of crankcase pressure over atmospheric pressureto exhaust blow-by gases to the manifold. No gases are allowed to ow outof the sealed crankcase to the atmosphere. Also, the usual substantialair intake directly from the atmosphere to the crankcase is eliminated,to thereby control sludging due to cold air flow and dust into thecrankcase.

Extensive testing and use of the patented system on vehicles of varioustypes has proven its uniqueness, operativeness, and advantages. However,recent testing and use of the system on engines of road-type vehicleshaving engines at least partially worn, has shown the necessity of 'amodification of the system for optimum performance under theseconditions.

It has been found that worn engines employing the novel system on asealed crankcase experience a substantial crankcase vacuum or negativepressure when the vehicle is decelerating under closed throttleconditions. Closed throttle deceleration typically occurs when a vehicleis using the engine as a braking force, for example, when going down along hill. The vacuum is caused by the continued reverse flow of gasesfrom the crankcase through the engine cylinders around the pistons tothe combustion chambers, instead of vice versa.

This phenomenon and its result can be explained as follows: An engine isnormally operating as an air pump. Air is pumped through the carburetorand induction system by the downward motion of the piston. During thistime, the intake valve is open. The intake valve is then closed and theair mixed with fuel from the carburetor) is compressed by the upwardmotion of the piston. The charge is then red by the spark plug,

pushing the piston downward for the power stroke. The

exhaust valve is opened after the power stroke and the piston returns tothe upward position, pushing the burned exhaust gases into the exhaustmanifold and out to the The amount of air being pumped through theengine depends on the position of the carburetor throttle plate. Duringdeceleration, with t-he throttle plate closed, practically no air ispumped through the engine because of the restriction at the carburetor.The pumping eifort, however, is being continued by the pistons. Theresult is that a high vacuum (up to 26 Hg) is created in the intakemanifold. During the intake stroke of the piston, this vacuum is alsopresent in the combustion chamber and the combustion cycle producesrelatively little pressure rise in the combustion chamber. Since theaverage combustion chamber pressures during deceleration are well belowatmospheric pressure, crankcase gases are drawn past the piston ringsinto the comice bustion chamber, and past the intake valve-to-valveguide clearance into the intake manifold. As an engine wears, the amountof gases drawn from the crankcase during deceleration increases, whichreduces crankcase pressures below atmospheric pressure to such an extentas to be detrimental.

It is an object of this invention to provide a pressure operatedcrankcase ventilation system as useful for worn engines of road vehiclesas engines in good condition, by providing a crankcase ventilation capthat prevents any crankcase exhaust flow to the atmosphere, but alsoprevents any substantial vacuum or negative pressure from forming in thecrankcase.

It is another object of this invention to provide an internal combustionwith controlled gaseous flow and complete pressure control between theintake manifold, the crankcase7 and the atmosphere, to effect optimumoper ating conditions with minimum sludge formation in the crankcase andno exhausting of noxious fumes from the crankcase to the atmosphere.

Still another object of this invention is to provide a crankcaseventilation system useful for any internal combustion engine withoutadjustments or modifications to suit the particular engine, and whichremains highly effective to control gaseous flow in worn engines of roadvehicles.

A further object of this invention is to provide a crankcase exhaustcontrol system that prevents exhaust outflow to the atmosphere andadmits small controlled amounts of air to the crankcase from theatmosphere just sufficient Ito prevent detrimental excess vacuum butsmall enough to limit sludging to an insignificant amount.

Another object of this invention is to provide a crankcase ventilationsystem especially useful for worn engines lthat are subjected to closedthrottle deceleration.

Another object of this invention is to provide a novel crankcase lillertube cap with the capacity of controlling atmospheric air intake into asealed crankcase in regulated small quantities to prevent substantialcrankcase vacuum, by effecting one-way ow control to the crankcase, andpreventing exhausting of noxious fumes to the atmosphere while allowinglimited inux of atmospheric air with minimum sludging.

These and several other objects of this invention will become apparentupon studying the following specification in conjunction with thedrawings in which:

FIG. l is an end elevational view of an engine of this inventivecombination;

FIG. 2 is a side elevational view of the novel oil filler tube capforming part of this system;

FIG. 3 is a sectional view of the cap in FIG. 2; and

FIG. 4 is a sectional elevational view of the pressure ow control partof the novel system.

The novel system 10 illustrated in FIG. 1 includes an internalcombustion engine 12 having a crankcase 14, an intake manifold 16, andan oil pan 18, and a filler tube 20. The system includes gaseous Vaporflow control means 2.2 from crankcase 14 to intake manifold 16, andincludes crankcase vacuum relief means 24 in the rform of an oil fillercap on filler tube 2i).

The ow control cap -24 is formed of a housing shell 26, having arecessed area 28 to tit over the iiller tube 20. The lower peripheraledge of the housing includes a planar, annular retention groove 30receiving and retaining an annular resilient ring 32 preferably of aresilient rubber material to retain the cap on the filler tube byfriction, and to seal the connection.

An annular dividing partition 34 extends across the central portion ofthe housing between its ends. It includes a central depression 36forming a spring seat 37. The depression has an axial control opening 38within the peripheral spring seat. The cross section of anyYtheperipheral inner wall `of housing 25.) The pocket of the U receivesan annularresilientstop 40ct rubber for abutment of the upper end of thefiller tube Y2.1i'. An Y upper annular valve seat 42 rests upon and issecured to the Vparti-tion'lid.4 g

An annular filter Y44 is positioned inthe upper halfrof Vthecap betweenthe upper end andjthe partition. I t is .between thecentrgalkvpassageway` portion of the cap and a v plurality of atmospheric inletports 46.l `Consequently, a passageway meansis'forrned from ports 46through posits on the butterfly valve .tend to be washedoli by the Y tothe engine... ThereforeLto relieve thisV condition, when the pressurediterential between the atmospheric standard pressure land the negativecrankcasekpressure or vacuum becomes a predetermined amount, "thepressurejdifferf ential Yshifts the plate check valve-4`8 against thebias of valve port 47, through depression portand cavity Y28 l to thefillery tube. ,This passageway and more specifically valve port 47, isnormally closed lbyna plate type, oneway check valve 48.vbiased; byman1annular compression springrSlOagainst Yvalve seat` 42. j Thebiasingforce of this springfis calculated to cause the valve Vto openonly with Ia predetermined pressure differential between atmospheric airat ports/46v and a negativer crankcase presf morebspeifcally V totlrieintake manifold 16,-is achieved with ow control mechanismY 22.. .y

:This `flow controlY mechanism includes a conduit-formed by connector60, rubber hose 62 between this connector ynector.ttfbetweenthe central`portion Y64 and an outliow conduit 68` from `the side pan .'20 of` theengine block. Preferably, `an oilsepaprator 72 is attachedv tothe insideof the side pan toy lprevent 'n oil flow uptheconduit system.

g A buttery valve-76 is mountedon ja pivot axis Y'Z8 in the centralportion V64` to close Voi` the Vpassage when' closed, and allowgaseousowrfrom the crankcase to thev intake manifold whenropenedfvary'ing.amountsa Ay pivotv link 8*,0 is'afxed to' shaft 78 externally ofconduit section 64'. The upper end of `this/link 80 is pivotallyattached y toa cross .reeiprocable 1ink782, the other endof which isaixed -to` retentionA plates 84' on OplDOsite sides of diaphragm'y'actuator' 86. This diaphragm 86 isY generally l circular in'configuration 'with link-.82 attached vto. the center thereof;Thelperiphery' of the/diaphragmA isf retained between two halves 9i) and92 of'a pressure control housing. This pressure control housing has oneside Vor chamberreriposed to atmospheric :pressure through ports 94, andtheother vside vexposed to crankcase. pressureV through'k a crankcasepressure sensing Stube 96. This tube extends from this chamber down toVtube portion64 onv the crankcase sideof'buttery valve`76. v

In operation, check valve`48i in the liller cap is normally. biased to a'closed position.V operating :conditinsfblwaby occurs `from thecylinders sure'v above' atmospheric.

phragm 86 overthe atmospheric norm or standard, to shift the diaphragm.This shiftsthe link-agegto rotate the bu-ttery. valve a proportionateamountandrjallow crankcase jgaseous flow past the valve into the intake,

manifold. .As soon as the. .pressure differential disappears the lvalveis closed. lThe butterfly valve itselflis 'not responsive to a pressurediiferential between the intake 'manifold andthe crankcase.

Itis not opened by manifold va-cuum. Rather. the pressure responsivemeans or diaphragmr 86 which controls the valve, opens None ofthecrankcasefvapors moveinto Undernormal4 engine Y of the engine pastthe'pistons to increase crankcase pres- The crankcase pressure in theconduit creates apositive pressure diiferential on diaspringk Thisvallows fent'ry off a small controlled amount of filteredA atmosphericair into the crankcase to eliminate*A `this differential. It willbezr'ealized that the amount ofair necessaryl'tofrelieve the. vacuum'`is normally insignificant so' that sludging. caused yby'e'nt-r'y of coldair into the crankcase will not be ,a problem..A

Therefore, nofmatter whatthe condition of the engine .or the conditionsof operation, the gaseous pressure conditions and ow .are completelycontrolled throughout the crankcase and intake manifold system of theengine, to maintainfat at optimum. performing conditions. lCold airentry into'th'e crankcase is Akept-atfa minimum. The crankcase .issealed 'to prevent vexhausting Aof noxious fumes to the atmosphere.

Additionall objectsA of this -inventionfwillfoccur to those skilled inthe art upon studying the foregoing form of this invention and theprinciples involved.` Also 'it is conceivable that certainstructuralmodifications can be made in'thesystein described -or in thevalvingfmechanism withy out departingfrom the inventivexconcept taught.,Therefore, this invention isvntto be limited to the particular detailsof the prefr'redffor'm'illustrated,fbut.only by the scope of theappendedgclaims and the Areasonably equivalent structures to thosedettined therein.

Ivclaim: f K f. g Y K i1. An. engine ,assembly comprising: an internalVcombustion engine including a sealed crankcase and intake manifoldmeans; conduit vmeans extending-from said sealed crankcaseto said intakevmanifold' means; gaseous iiow regulator means for said conduitincluding a valving means anda vpressure responsive. element operativelyassociated with saidvalving'm'eans to open and close it;.said pressure Yresponsive-elementbeing responsive to the pressure differential betweenpositive crankcase pressure over a standard pres-sure ,to'open saidvalving'means and allow tlow of gases from said lcrankcase to` saidintake'manifold upon an increase in crankcase'pressure over saidstandard pressure and `causing said valving means to close upon adecrease 'of crankcase pressure to said standard pressure; and a onewaynormally closed Y valve bet-Ween said crankcase and thesurroundingatmospheresubjecty to opening upon Y av decrease in crankcasepressure a'predetermined amount below afmsplieric pre'ssure't'o lopenand admita small Vquantity of atmospheric air to said crankcase untilcrank- 1v' case pressure increasesabovesaid predetermined amount.

'Y 2. An engine assembly comprising: an internal combustion engineincluding asealed crankcase and intake mani- :fold "'r'neansgrconduitmeans eritendin'gV from said sealed crai'ikoasey tosaidintakemanifoldmeansg gaseous flow regulator means for said conduitincluding a'valving means v and a pressure responsive elementoperativelyyassociated .with saidvalvingrnieans to open and'close it;said pressure responsive,elementfbeingresponsive to thel pressure dif-I' ferential between positive crank-case pressure over aVstandard-pressureJt-o open'said vali/ingv means and allow-flow of gasesfrom'said cran-lecase to said intake mani-foldupon an increaseincrankcase pressure over said standard pressure, and responsive to closesaid valving'meansupon a decrease in crankcase pressurebelow'saidst'andard pressure; a r'one-.way {normally-closed liow'controlvalving means'between said crankcase and agaseous supply'means,

preventingfoutllow `ofgases from said ycrankcase to the 5 atmosphere andresponsive to open with a decrease of crankcase pressure below apredetermined minimum to allow gaseous inow to increase said crankcasepressure above said minimum.

3. An engine assembly comprising: an internal combustion engineincluding an intake manifold and a sealed cr'ankcase; a gas conduitbetween said manifold and crankcase; crankcase pressure responsive ilowcontrol valvng means for said conduit for blow-by gases from saidcrankcase to said manifold; said tlow control valving means beingsubstantially responsive only to positive crankcase pressures over astandard pressure; and negative pressure relief means for saidcrank-case to relieve negative pressure occurring in said crankcase morethan a predetermined value with respect to a standard pressure.

4. An engine assembly comprising: an internal cornbustion engine havingan air intake means and a sealed crankcase; ilow conduit means from saidcrankcase to said intake means; valve means in said flow conduit'means,and valve actuator means responsive to a predetermined diterential ofcrankcase pressure over atmospheric pressure to open and allow flow ofblow-by gases from said crankcase to said intake means; and normallyclosed, oneway, vacuum-relief valving means between said crankcase andthe atmosphere, responsive to a predetermined differential ofatmospheric pressure over crankcase pressure to open and admit acontrolled quantity of atmospheric air to relieve the vacuum.

5. An engine assembly, comprising: an internal combustion engine havingan air intake means, a sealed crankcase, and a iller tube; flow conduitmeans from said crankcase to said intake means; valve means in said flowconduit means, and valve actuator means responsive to a predeterminedpressure differential of crankcase pressure over atmospheric pressure toopen and allow ilow of blow-by gases from said crankcase to said intakemeans; oil ller cap on the end of said filler tube including seal meansbetween said cap and liller tube; passage means through said capcommunicant with said tube and the atmosphere; and normally closed valvemeans in said cap, openable against a bias only in response to apredetermined pressure differential of atmospheric pressure overcrankcase pressure to allow inflow of regulated quantities ofatmospheric air to relieve said pressure differential.

References Cited by the Examiner UNITED STATES PATENTS 2,716,398 8/55McMullen 123-119 3,080,994 3/ 63 Chausson 222-44 3,083,862 4/63 BowdenZ22-44 3,108,581 10/63 Humphreys 123-119 3,145,697 8/64 Barr 123--1 193,160,487 12/64 Risse et al 55-417 RICHARD B. WILKINSON, PrimaryExaminer.

KARL I ALBRECHT, Examiner.

1. AN ENGINE ASSEMBLY COMPRISING: AN INTERNAL COMBUSTION ENGINEINCLUDING A SEALED CRANKCASE AND INTAKE MANIFOLD MEANS; CONDUIT MEANSEXTENDING FROM SAID SEALED CRANKCASE TO SAID INTAKE MANIFOLD MEANS;GASEOUS FLOW REGULATOR MEANS FOR SAID CONDUIT INCLUDING A VALVING MEANSAND A PRESSURE RESPONSIVE ELEMENT OPERATIVELY ASSOCIATED WITH SAIDVALVING MEANS TO OPEN AND CLOSE IT; SAID PRESSURE RESPONSIVE ELEMENTBEING RESPONSIVE TO THE PRESSURE DIFFERENTIAL BETWEEN POSITIVE CRANKCASEPRESSURE OVER A STANDARE PRESSURE TO OPEN SAID VALVING MEANS AND ALLOWFLOW OF GASES FROM SAID CRANKCASE TO SAID INTAKE MANIFOLD UPON ANINCREASE IN CRANKCASE PRESSURE OVER SAID STANDARD PRESSURE AND CAUSINGSAID VALVING MEANS TO CLOSE UPON A DECREASE OF CRANKCASE PRESSURE TOSAID STANDARD PRESSURE; AND A ONE-WAY NORMALLY CLOSED VALVE BETWEEN SAIDCRANKCASE AND THE SURROUNDING ATMOSPHERE SUBJECT TO OPENING UPON ADECREASE IN CRANKCASE PRESSURE A PREDETERMINED AMOUNT BELOW ATMOSPHERICPRESSURE TO OPEN AND ADMIT A SMALL QUANTITY OF ATMOSPHERIC AIR TO SAIDCRANKCASE UNTIL CRANKCASE PRESSURE INCREASES ABOVE SAID PREDETERMINEDAMOUNT.